Compound metal body and process of producing same.



J. F. MONN OT.

GOMPOUND METAL BODY AND PROCESS or PRODUCING SAME.

APPLICATION FILED APB..24, 1907.

909,924. Patented Jan. 19, 1909.

- vlllllllllllllll A 'Argyll '11,1114' Il l WVIIIIIIIIIIILYI "Y l kl WITNESSES:

Max flwrln ATTURN EYS UNITED NsTATEs PATENT oEEIcE.

JOHN F. MoNNoT, or

COMPOUND METAL BODY AND PROCESS 0F PROVDUGING SAME.'

Specification gif/Letters Patent. Application filed April 24, 1907. Serial No. 369,996.

Patented Jan'. 19, 1999.

To all whom it may concern: I

Be it known that I, JoHN F. MoNNo'r, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented certain new and 4useful Improvements in Com ound Metal Bodies and Processes of Pro ucing Same; and I do hereby declare the following to be a full, clear, and exactdescription of the same, such as will enable others skilled in the art to which it appertains to make and use' the same.

Aluminum, magnesium, beryllium (glucinum) and similar light metals, as well as such light alloys as magnalium, are eminently desirable for many purposes in the arts where an article extremely light but 'still of metal is required; but where such articles' must be made of parts lsecured together, as in jewelry, knife-handles, and many other similar composite structures, these metals are not as extensively used as their specific gravity and other properties would indicate owing to the practical Adifliculties attending brazing, soldering and similar operations. These difficulties are largely due to the fact that these light metals and alloys( are nevertheless as readily worked as the commoner metals; taking solder like copper or silver. If a bar of aluminum be covered with and have united to it a thin impervious coating, even lilmlike, ofa readily solderable metal like copper or silver, it may be readily worked4 by common processes and tools, the film coating taking the solder and preserving the surface of the underlying I netal from oxidation or other contamination. lThe' coating metal may bc, and usually is, too small in amount to nake any substantial difference in the specific gravity of the article. If its superg cial appearance be preferable to that of the base metal, as in thecase of aluminum with silver coating, the coating may be left, but if the appearance of the underlyinfr metal is required the ilm coating of theothcr metal can readily be removed, chemically or mechanically, from the surface beyond the solder line. O r, the coating may be readily elcctroplated if desired since the film of coating metal will take electrocoatings, as of gold, nickel, etc. Light metals do not themselves readily take such electroplatings. It

vis necessary however that the coating film( be impervious, eitherl for soldering or for electrocoating, to prevent access of corrosive soldering uids or electroplating fluids to the ,readily corroded light metal beneath.

For many articles, it 1s, as stated, desirable to leave the coating, if of an ornamental resistant metal, such ,as copper or silver, in place, as the surface appearance and prop- NEW YoRK, N. Y., `AssIeNoR To DUPLEX METALS COMPANY, or NEW YORK, N.y Y., 'A CORPORATION or NEW YoRK. v

erties of aluminum, etc., are frequently not desirable. For instance, in culinary utensils, such as kettles, while it is desirable to have a kettle as li ht and as heat conductive as it is when ma e of aluminum, nevertheless it is not so desirable to have the -aluminum surface appearin Aluminum is read'- ily attacked by foo s containing salt, as sou and furthermore it is so soft as to mar rea il and not to take a good polish, so'that corro ed spots or dents li l up with dirt and are not readily burnished. -It is obvious that for this purpose the protecting coating or films must bel a non-porous, as state 'to prevent access of soldering liuids or air to the underl ing light metals, and must be` firmly andy permanently attached thereto, forming a union of 'great mechanical strength. 4Fromtheir -porosity and little adherence, electrocoatings dol not 'answer .these requirements, and, moreover, they are inordinately diliicult to apply 'to these light andreadily oxidizingmetals. Neither can suchcoatings be filmed-on in the usual ways of-metal coating as in"tinning yand galva nizing, the stated oxidation phenomena preventing adherence of metal basalt-andv Hash coats so ap lied.

I have dlscovered that ifa body, as a bar, of aluminum in a suitably heated state and with a clean metallic surface have applied thereto a mass of melted copper or silver, preferably at a heat considerably above its meltin point, the surface of the bar' and the mo ten metal where contacting, unite so quickly withdrawn, brings with it a cohering film of the said other metal united by i the described type o f union. The converse treatment is also applicable; z'. e., the plunging of a bar of silver or copper intoa mass of melted aluminum, but the former treatment is preferable for this purpose, as it is usually desirable to have the aluminum for the core.

Where the bar of aluminum, etc., is not to be drawn down or otherwise worked, the lm of the coating metal so applied is convenient for many purposes, but generally I prefer to go further; welding on to the filmed bar a further amount of silver or copper at a more' convenientl casting temperature.

This gives an ingot or lbar or other shape consisting of a core coated on one' or more sides with a layer of the coating metal of appreciable thickness. Upon drawing down the bar into wire or rolling it into plates, the coating metal will be found to 'follow the base metal throughout its extension and to persist as a coating of substantially the same relative thickness as that on the original ingot, the two metals cohering perfectly togegner, so as to be inseparable by neat., sliortof the melting point or operation of cutting tools, or by mechanical stress. If a thick bar of aluminum have autogenously welded thereto by the described process a coating of silver, of, say, 3 per cent.. of the whole mass, the thinnest wire or plates extended froni the compound bar will also be found to have 3 per cent. of silver. The coating metal having been put on and solidified in place from a fluid state has the general property of fluids and set fluids of being poreless; and in the described extension it 4heated ulider conditions precluding oxidation. This heat` may be just enough to insure a dry surface, or it may be somewhat higher. Said bar, or ingot, as it will be termed hereafter, is then withdrawn under conditions precluding oxidation and other surface deterioration, and is then plunged momentarily into a bath of silver, copper, or other suitable metal of relatively high melting point, preferably a metal which is not readily oxidizable; such metal being maintained in a very fluid condition, and preferably heated considerably' above its melting point. If only a thincoating of copper or other coating metal is desired, the ingot may be Withdrawn after a few seconds, under-conditions precluding oxidation, and allowed vto cool; and when cool will be found to be coated with-.a thin cohering film of the coating metal having the desirable properties of a metal solidified from the fluid state.A Such coating so formed is very thin. If a thicker coating is desired such coating may be formed by confinino` a portion of the molten metal, of suitarble thickness, in contact with the surface of .the aluminum body, and then withdrawing said aluminum body and confined layer and permitting the latter to solidify. The compound ,ingot thus produced is then preferably- Worked, as by rolling, pressing, hammering or like mechanical operation. As an alternative method, the ingot may be Withdrawn,

under circumstances precluding oxidation, after a few seconds contact with the molten metal, and then immersed 1n a secondbath of molten metal maintained, if desired, at

showsl in detail section the construction of' bottom plate and lower portion of casing preferably employed.. Fig. 3 shows a sectional view of another form of casing which may be employed.

n Fig. l, l is a preliminary heating chamber for the ingot or core, 2 a furnace for heating a Crucible 3, containing a body of molten'coating metal, and 4 designates a second Crucible, which may or may not be used, as desired.

5 designates'a power hoist, here. shown as an electrical hoist, mounted on a suitable track so that it can be-'moved from place to place; and from said hoist is suspended, by means of a porter bar 6, the ingot 7,

which is the object to be coated. Said ingot of which is ieXible, said pipe provided with a three-way lvalve l0. This pipe and the valve l0 are provided for supplying to the casing, when desired, an atmosphere of indifferent or neutral gas, such as producer gas. Casing 8 has a weighted head 11 which insures that when the casing is lowered intov the molten metal it shall sink therein to the de th desired. 1'2 designates a bottom plate ortho casinff: arranged to be secured to the ingot 7 itself?, by means of a screw 13. Said bottom plate .is provided with a raised rib or ring 14 matching a corresponding groove 15,- in the lower edge of the casinor and adapted to coact with said groove 'make a tight joint. For raising and lowering the casing 8 with respect to the ingot 7, a special hoist 16, suspended like porter bar 6 from hoist 5, is provided. It has, in

- the form shown, two winding drums 17 upon the crucible 3 containing which are wound two cables 18 connected to opposite sides of the casing, so that said casin may be raised and lowered truly vertica ly.

loose removable cover 19, which cover is designed to exclude air from the molten metal so far as possible, and is removed only when and so long as necessary to lower an ingot and casing into the cruclble, or to inspect the molten metal, or for similar reason. To further exclude air-from the surface of the molten metal, I cover so much of its surface as possible with a layer of char` coal, a'ring 20 of refractory material which floats on the surface of the molten metal serving to maintain a clear'space in the center for the passage of the ingot and casing.

As an alternative tothe above described apparatus for carryin out my process, I may use th atshown in Iig. 3, which is much the same as that above described except that thev casing 8 is provided with inlets 28 in its sides, said inlets arranged to be closed 'at will by a sliding shield or..valve 241. In carrying'out the process with. this apparatus the casing without the bottom plate 12 -thereon is placed over the heating chamber. 1, said 4casing being at the time filled with a protective atmosphere as above described, and the porter bar is lowered down through the casing, secured to the ingot or core to be coated and raised up into said casing lagain w1th the said ingot or core.

The casing with* the core 7 within it isl then moved to one side, the bottom plate 12 applied, and then the casing is moved over molten coating metal, fand is lowered 1nto vsaid molten metal; the valve or closure 24 being raised as the openings 23 come to the surface of the molten metal so that said casing ills through said openings 23. The casing with `ingot and molten metal within it is then raised and the'molten metal allowed to cool as before. In carrying out the process in this way, the protective atmosphere within the I customarily provide the Crucible with a' casing when the lling holes 23 are open, protects' the surface of theingot and the molten metal which enters the casing against oxidation; and in fact no aircan enter the casing, because the holes 23 are submerged in the molten metal almost instantly after the closure 24 is raised, and during the pos.

sible brief instant while said openings are open but not completely submerged the outrush of gas from the casing will prevent the entrance ofl air.

To hasten the filling of the casing with molten metal, and to prevent trappmg of gas in the molten metal as it solidifies, I

lpreferably apply suction to the outlet 25 Instead of applying the coating in a single operation, as above described, I may apply it in two operations, film-coating the ingot v.

7 by immersing it momentarily in the molten metal in crucible 3 and then, without lowering thecasing into the molten metal, withdrawing the ingot, now covered with a thin film-coatingl formed by the action of the molten metal, back into the casing, moving said` casing over the crucible 4, the molten metal in which is preferably at ordinary cast-ing temperature or thereabout, applying the bottom plate vto the ingot, lowering said ingot into the metal of bath 4 and thereafter lowering the casing and so confining against the film-coated surface a layer of the metal from bath 4, and then withdrawingthe casing with its contens `from the molten -metal and permitting the molten metal within it to solidify. Or, instead of using the Vapparatus of Fig. 1, that of Fig-'3 may be used; the consequent variation in the procedure just described being obvious.

In application tiled September 6, 1906, Sr. No. 333,570, I have described and". claimed a method of forming weldl-like unions lbetween unlike metals by contacting the surface of one such metal Vwith a molten mass of the other such metal maintained at areactive condition much above its ordinary melting and casting temperature, which'reactive condition is termed by me the super. molten condition. The supermolte'n condition is particularly necessary vwhen it is sought to unite non-ferrous Ametals such as copper, silver and aluminum directly to such c ondition;

that the molten metal'be in the supermolten condition but it is convenient to have it in and such molten metal should always be quite fluid. In forming the coating by the double dipping operation just above described, using both crucibles of the furnace, the metal inl crucible 3, Whether or not it be the same as the metal in crucible 4, will ordinarily be maintained at considerably higher vtemperature than that of Crucible 4. By a reverse of the above operation, aluminum may be applied to gold, silver, copper, and, When the molten aluminum is maintained at the supermolten condition, to iron.

The coating process herein described is applicable tothe procuring of autogenously welded coatings on aluminum or other noble metals, like gold. Gold-silver alloys; goldcopper, silver-copper and kgold aluminum alloys may be so Welded on, obtaining the distinctive appearance thereof. Where a very thin coating of gold is placed on the original ingot and co-extension of the joined metals carried to a high degree, the gold coatinc' may be obtained as an excessively thin fi m, showing the optical properties of -such thin gold films.

In stamping out articles from a compound plate formed in the manner described, by the use of a round-edged or obtunding tool,

the lcoating metal may be caused to flow or extend beyond the cut edges of the base metal, thereby shielding such edges.

Various uses for the compound metal produced as herein described will su gest themselves.

One important feature o the invention is that it provides a satisfactory method of joining aluminum articlesor surfaces by soldering or brazing-which has' not been found commercially practicable heretofore. lVhile aluminum and the other light metals and alloys do not solder or braze readily, silver and copper do solder and braze readily. By coating aluminum surfaces with copper or silver in the manner above described, such surfaces may be united by brazing or Welding together the copper or silver surfaces in the manner customary in brazing silver or copper. This opens up a Wide field for the use of aluminum and aluminum coated metal. For instance, in making match boxes or similar articles of aluminum, a bar or ingot of aluminum mayv be coated with 2 or 3 per cent. of silver 1n the bodies which consists in contacting aluminuml and another non-ferrous metal of relatively high melting point, one of said metals in a solid condition, the other in a .freely liquid molten condition, and causin a layer of such molten metal to form on an solidify on the surface of such solid metal.

2. The process of making compound metal bodies which consists in contacting a solid base of aluminum with a non-ferrous metal, the latter at a temperature much above its melting point, and causing a layer of such metal to solidify on the aluminum surface.

3. The process of making compound metal bodies Whlch consists in contacting a base of aluminum with silver at a temperature much above its melting point and cansino a layer of such silver to solidify on such aluminum surface.

4. The process of uniting light-metal articles which consists in covering such articles with a Welded-on coating of a' solderable metal and 'soldering together the surfaces to be united.

5. The process of uniting light-metal articles Which consists in covering such articles 'with a weldedon coating of silver and other metal bodies which consists in covering such aluminum articles with a weldedon coating of silver and causing it to solidi thereon, and soldering the so-coated alumlnum article with another solderable surfac with Whichit is to be united.

7. The process of making compound metal bodies which consists in contacting aluminum and another non-ferrous metal of relatively high melting point, one of said metals in a solid condition, the other in a freely liquid molten condition, and causing a layer of such molten metal to form on and solidify on the surface of such solid metal, and removing the coating from the unsoldered surfaces.

8. Asa new article of manufacture, a compound metal article comprising abody of a metal of vthe light-metal group having inseparably united and cohering thereto a dense, porelcss and impervious layerof an unlike non-ferrous metal of high melting hering t creto avlayer of a readily-solderpoint, said joined metals being in metallic contact at all points between abutting sur, faces and being molecularly-united."

9. As a new, article of manufacture,acom pound metal article comprising a body of a metal of the light-meta group having inseparably united and cohering thereto a dense, poreless and impervious layer of a high-melting noble metal, said joined metals being in metallic 'contact at all points,V .between abutting surfacesand being molec ularly united.

10. A s a new articl'e of manufacture, a compound metal article comprising a Ibody of aluminum having inseparably united and cohering thereto a dense, poreless and impervious layer of an unlike non-ferrous metal of high melting point, said joined metals being in metallic contact at all points between abutting surfaces and being molecularly united. i

1l. As anew article of manufacture, a compound Imetal article comprisinga body of aluminum having inseparably united and cohering thereto a dense, poreless and impervious layer of silver, saidjoined metals being in metallic Contact at all points between abutting surfaces and being molecularly united. A j i 12. As a new articleA of manufacture, a compound metal article comprising a body of'metal comprising aluminum', said body having inseparably united -and cohering thereto a dense, poreless and .impervious layer of silver,vs'aid joined metals bein in metallic contact at all points between4 a utting surfaces and being molecularly united. 13. A s a new article of manufacture, a. compound metal article com rising bodies of metal of the light-meta group, each able high-melting nonferrous metal, said joined metals being in metallic contact at all points between abutting surfaces and being molecularly united and the said readilybodies being soldered together.

14. As a new article Aof manufacture, a compound metal articlevcom rising bodies of aluminum, each such bo y having inseparably united and coherin thereto a layer ofa readilysolderable h1gh-melting non ferrousmetal, said joined metals being 'abutting surfaces yand being -.molecularly united, the'said readily solderable layers of different aluminum bodies being soldered together.

15. As a new article of manufacture, a com oundmetal article comprising bodies Vof a uminum, each such body having inseparably united and cohering thereto a layer of silver, said joined metals being in metallic contact at all points between abuttin surfaces and being molecularly united an dered together. j

16. As a new article of manufacture, a compound metal article comprising two or more at the point of union carrying an inseparably united and cohering layer of silver, the joined silver and aluminum being in metallic contact .at all points between abutting surfaces and being molecularly united an being united to a similar silver layer of another of said bodies by a solder union.

in the presence of two witnesses.

. JOHN F. lMONNOT Witnesses:`

such bod having inseparably united and co- BYRON E. Emma,l JAS. K. CLARK.

in metallic contact at all points between` the silver layers of'said bodies being solsolderable layers of diiferent light-metal united bodies of aluminum, each such body4 In testimony whereof I afliX my signature, y 

